My favorite fruits for clafoutis are cherries and berries. Make sure they are sweet and tasty before using them. Using heavy cream in addition to milk makes this dessert rich but also super delicious. If you want to keep things light and leave out the cream, use a total of 1 and 1/4 cups milk instead. A cast iron skillet retains the heat well, but if you don’t have one you can use any 9-inch dish. Use a shallow dish if you have one. Serve the clafoutis while still warm.
Preheat the oven to 350°F/180°C. Butter a 9-inch cast iron skillet or pie pan. In a medium bowl, whisk eggs, sugar, and salt for about a minute until well combined. Add flour and whisk until smooth and lump free. Whisk in melted butter, followed by the milk, heavy cream, vanilla extract and lemon zest. Make sure that the mixture is completely smooth. Pour batter into prepared pan. Scatter fruit onto the batter.
Bake for 35-40 minutes until the clafoutis is just set (it's ok if it's still wobbly in the center) and golden at the edges. Let cool slightly until lukewarm. Dust with powdered sugar, if you like. Cut into wedges and serve.